304 SE EVERETT MALL WAY PANERA BREAD Geotech Report 2025-07-25

KA No. 092-12004 August 24,2012 Page No. 9 If debris exists in the fill material at the site, there is a possibility that this material may obstruct some piles. There should be contingencies in the budget and design for additional/relocated piles to replace piles that may be obstructed by debris in the fill. Due to the relatively small slenderness ratio of pin piles, maintaining pin pile confinement and lateral support is essential to preventing pile buckling. Pin piles should not stick above the finished ground surface. Vertically driven pin piles do not provide meaningful lateral capacity. However, battered piles can provide a lateral resistance component. The structural engineer should determine the degree of batter, and the number and locations of battered piles. We recommend that the battered piles be embedded a minimum of six inches into the foundation concrete and that sufficient steel reinforcement be placed around the piles to ensure a good connection to the foundation. Floor Slabs and Exterior Flatwork Floor slabs supported on the medium dense or firmer granular materials may be designed using a modulus of subgrade reaction (k) value of 200 pounds per cubic inch (pci). In areas of undocumented fill, floor slabs can either be placed on one foot of granular structural fill or on pin piles. Floor slabs placed on one foot of structural fill overlying soft/loose undocumented fill are at risk of differential settlement. If settlement of the building floor slab cannot be tolerated, then the slab should be constructed on pin piles extending through the undocumented fill material and into dense or better native soils. Alternatively, the slab could be supported on structural fill extending to the medium dense to dense native soil. If a slab-on-grade structure is proposed and reducing floor dampness is desired, such as in areas covered with moisture sensitive floor coverings, we recommend that concrete slab-on-grade floors be underlain by a water vapor retarder system. The water vapor retarder system should be installed in accordance with ASTM Specification E164-94 and Standard Specifications E1745-97. According to ASTM guidelines, the water vapor retarder should consist of a vapor retardant sheeting underlain by a minimum of 6-inches of free-draining (less than 5 percent passing the U.S. Standard No. 200 Sieve based on the fraction passing the No.4 sieve),open-graded 3/a-inch clean crushed rock. The vapor retardant sheeting should be protected from puncture damage. The exterior floors should be placed separately in order to act independently of the walls and foundation system. All fill placed in the building pads should be structural fill. It is recommended that the utility trenches within the structure be compacted, as specified in our report, to minimize the transmission of moisture through the utility trench backfill. Special attention to the drainage and irrigation around the building is recommended. Drainage should be established away from the structure and should be maintained throughout the life of the structure. Water should not be allowed to accumulate adjacent to the structure. Over-irrigation within landscaped areas adjacent to the structure Krazan&Associates,Inc. Eleven Offices Serving The Western United States